* RST instructions are just a CALL instruction to a fixed address baked in the instruction itself.
* Despite what the syntax of the instructions JP (HL/IX/IY) suggests, PC will be loaded with the contents of the register itself, not the indexed value. Those instructions should be understood as JP HL/IX/IY.
* The instructions LD A,A, LD B,B, LD C,C, LD D,D, LD E,E, LD H,H and LD L,L are useless. Their existence is just a side effect of how instructions are encoded as opcodes in the CPU.
* The instructions LD (nn),HL and LD HL,(nn) exist both as standard opcodes and ED-prefixed opcodes.
* The 16-bit instructions ADD HL,ss, ADC HL,ss and SBC HL,ss exist but not the instruction SUB HL,ss.